WEST PALM BEACH, Fla. — Federal prosecutors argued Tuesday that a prominent Florida eye doctor tied to alleged political corruption ran a practice that was actually a well-organized scam that stole millions from Medicare.

Assistant U.S. Attorney Alexandra Chase told a federal jury during closing arguments that Dr. Salomon Melgen, 62, repeatedly performed unnecessary tests and treatments on his mostly elderly patients to “line his pockets.” He faces the equivalent of a life sentence if convicted of all or most of the 76 counts against him. Prosecutors say he stole up to $105 million between 2008 and 2013.

He is charged separately in New Jersey with bribing Democratic U.S. Sen. Bob Menendez, who has denied any wrongdoing. That trial is scheduled for the fall.

His attorney, Matthew Menchel, argued that Melgen made numerous billing and treatment mistakes that leave him open to lawsuits and possibly losing his medical license, but they weren’t intentional and therefore not a crime. He was an aggressive doctor who refused to give up on his patients when other doctors had, Menchel said.

“Patients testified that if it wasn’t for Dr. Melgen, their eyesight wouldn’t have been saved and improved,” Menchel said. “He was a kind and caring doctor who went out of his way to help his patients.”

But Chase said Melgen’s actions were not honest mistakes. Telling jurors that he ran an office designed to defraud Medicare, she pointed to tests that should have taken five minutes or more but were done in seconds, making them useless for a diagnosis but still billed to Medicare at the full rate. She pointed to tests and treatments Melgen billed on patients’ fake eyes. She pointed to potentially dangerous treatments performed on patients with no or minor eye problems. In 2012, Melgen received more Medicare reimbursement than any doctor in the country, nearly $21 million.

“Mistakes happen once or twice, here or there, but when they happen over and over again, they are intentional,” Chase said. Melgen stared straight ahead impassively during her two-hour argument, his family and supporters packing the courtroom.

Melgen became politically active in 1997, when he treated Florida Democratic Gov. Lawton Chiles, who appointed him to a state board. He was soon hosting Democratic fundraisers at his 6,500-square-foot (605-square-meter) North Palm Beach home and meeting party congressional leaders. That led to his friendship with Menendez, during which Melgen paid for trips that he and the senator took to France and to the doctor’s home at a Dominican resort. Menendez reimbursed Melgen $58,500 after the trips became public knowledge.

Federal prosecutors in New Jersey say Melgen’s gifts to Menendez were actually bribes. In return, they say, the senator obtained visas for the married Melgen’s foreign mistresses, interceded with Medicare officials when they began investigating Melgen’s practice and pressured the State Department to help Melgen with a business dispute he had with the Dominican government.